Warp knit fabric and method of



C. R. FSUHNS me@ 17, ma

WAR? KNITAFABRIC AND METHOD OF MAKING-THE SAME Original .Filed Jan. 15, 1941 I a n a a n JUA/3 J0 13d@ s l nl V f 4 according to an Patented Dec. 17, 1946 T o1-FICE WARP KNIT FABRIC MAKING T Charles R. Burns, West Reading,

Vanity Fair Mills, Inc., Reading, tion of Pennsylvania Original application January 374,219. Divided and this AND METHOD F HE SAME Pa., assignor to Pa., a corpora- 13, 1941, Serial No., application August 26, 1944, Serial No. 551,305

6 Claims. (Cl. (i6-192) The .present invention relates to warp knit fabric and the method of making the same, and has for `its basic object the provision of stretchable warp knit fabric possessing a greater amount of snap than is usually `present in known fabrics of this kind, and this application is a division of my application Serial No. 374,219 for Letters Patent No. 2,356,819.

The invention more particularly contemplates the provision of a stretchable warp knit fabric produceable on a usual warp knitting `machine of the type commonly known as tricot machines; the machine, however, being operated improved method in order to produce a fab-ric of usual knit construction which imparts to said fabric an increased .ability to stretch and, at the same time, supply the fabric with an inherent ability to snap back to its normal intended `and original form. It is one of the most important features of the invention to provide a warp knit fabric wherein the yarns `are so laid as to acquire a particular characteristic formation which gives the fabric an extraordinary degree of stretchabilty and snap.

VAnother important feature of the invention is found in the fprovision of a warp knit fabric whereincertain yarns are kso related with certain other yarnsas to assumea zig-zag or accordion formation, whereby said fabric, by reason of the zig-zag or raccordion formation of said certain yarns, inherently and constructionally acquiresan extraordinary degree of elasticity.

,Amongspeciiic objects of the invention is'the provision of-a fabric knitted in tricot fashion from a set of inelastic yarnsrand a set of elastic yarns, the inelastic yarns being knitted into a base fabric and the elastic yarns being laid in zig-zag direction and tied within said fabric in such a mannervas to produce a finished fabric of uniform surface `by preventing said elastic yarns from crawling or creeping which is known to be" Oilof the primaryoauses of the production of` al wrinkled effect in such fabrics.

`The invention .is specifically characterized in thatit results in the `production of fabric possessingagreat manydesirable advantageous features such as strength, ,elastic stretchability, and distinctive surface appearance.

Other important objects, features, and advantages of the invention will bein part obvious and in part pointed out hereinafter. i

`The 4improved fabric, in accordance with -the invention,.ismade on a tricot warpknitting machine employing a needle bar and two yarn guide bars respectivelyknown as the back guide bar and the front lguide bar. The needle bar is provided with a bank of needles which vary in number according to the gauge, and `each guide bar has a bank of yarn guides corresponding to the number of needles in the needle bar. The guide bars are slidable in reverse tudinally of the needle bar, each guide bar being controlled by individual cam or f cams. Both guide bars, moreover, are swingable transversely of the needle bar.

Also, in accordance with the present invention, every other yarn guide of the back guide bar is threaded with a warp yarn (preferablyan elastic yarn), ,and every yarn guide of the front guide bar is threaded with a warp yarn (preferably `an inelasticyarn). Thus there are twice as many inelastic yarns as there are elastic yarns.

According to one aspectof the invention, the back andfront guide bars respectively slide longif tudinally of the needle bar, at times in the same direction, and at other timesV in the opposite direc,- tion, `but the sliding motion of one guide bar (specifically, the back 4guide bar) occurs only in front of the needles, whereas the sliding motion of the other guide bar (specifically, the front guide bar) occurs either in front; of the needles.

of or in back 011V@ guide bar, thatis, the back guide bar, has a sliding motion longitudinally of the needle bar a certain number of needles at a timeV for the distance of .la predeterminedxed number of needles in onedirection and for the distance of a predetermined iixed number of needles in the other direction, and the other guide bar, that is, the front guidebar, has a sliding vmotion longitudinally of the needle bar a certain number of needles at a'time for 'the dis,- tance of a predetermined variable number Aof needles in one direction and forthe distance of a predetermined variable number of needles "in the other direction.

Thusyto give a specific example: Eachyarn in the back guide bar laps over rfour needles, one needle at a time, and then drops back `over four needles, one needle at a time, whereas` eaeh yarn in the front guide bar laps over'` one needle, under one needle, and drops back over one needle,

under o ne needle, and then laps over two needles,l

under one needle,` this relative lapping and dropping baek of yarns in the `rear and front guide bars being repeated throughout the length of the fabric.

As a result of this particular procedure, there is produced a Warp knit fabric consisting of courses knitted from the yarns in front of the directions longi- 3 guide bar, certain spaced courses being formed of non-reversing closed stitches on which the yarns in the rear guide bar are hung. Further, the particular procedure results in that the yarns in the rear guide bar are laid in zig-zag or accordionelike fashion so that said yarns, upon being relieved of the tension under whichthey are laid, tend to straighten out, causing the.

loops of the courses knitted from the yarns in the front guide bar to gather, accordingly producing a fabric having an increased ability to stretch and snap back, and possessing a characteristic surface appearance.

In order that the invention and its mode of operation may be more readily understood by those skilled in the art, I have, in the accompanying drawing and in the detailed description based thereon, set out the specic example of the invention hereinbefore mentioned.

. In the drawing:

. Figure 1 indicates they combined motions of the frontI and rear guide bars of a tricot machine operated to produce one fabric construction in accordance with the invention; Y

Figure 2 indicates the motion of the back guide barin the making of said fabric construction;

-Figure 3 indicates the motion of the front guide bar in the making of said fabric construction;

Figure 4 illustrates on a greatly enlarged scale the loop formation of the fabricconstruction as knitted on the machine; and i Figure 5 is a diagrammatic representation of one face of the fabric: construction upon being completed.

It is pointed out that, for the sake of clarity inillustration, the motion of the back guide bar is shown in heavy lines, and the motion of the front guidey bar is shown in light lines in Figures 1 through 3. Y llteferring to the fabric construction shown in Figures 1 to 5 inclusive, it will appear from Figure 1 of the drawing that in the manufacture of the fabric illustrated, two sets of Warp yarns II) and I2 `are employed, one set of Warp yarns I0 being elasticand the other set of warp yarns I2 being inelastic. It will be noted that the elastic yarns I andthe inelastic yarns I2 at times are laidin front of the needles I4 in opposite directions, and at other times are laid in front of the needles in the same direction, and that moreover, while the number of inelastic yarns I2 is equal to the number of needles I4, there are only half the number of elastic yarns I0.

The movement of the guides for the respective yarns I0 and I2 are represented separately in Figures 2 and 3. As clearly appears in Figurev 2, each elastic yarn I0 is moved, for instance, to the right in front of the needles one needle at a time for a certain number of needles, and then to the left in frontof the needles one needle at a time for a certain number of needles. In the example shown, the movement of each elastic yarn to the right and to the left is overfour needles, although it will be understood that such movement may be 'over a different number of needles than that specified in either or both directions.

` It is to be noted particularly that each elasticV yarn, in its movement to the right and to the left, does not lap around any one needle at any time, but is merely laid in a lengthwise position in front of the needles, the yarn at its reversal points indicated at I and I1 (Figure 2) becoming hung, as shown at I9 and 2l in Figure 4. Y

As shown in Figure 3, each. inelastic yal'n l2 two needles, under one needle,

is moved to the right over one needle, under one needle, so that the yarn is wrapped around the needle as shown at 23 in Figure 3, forming areversing closed stitch as shown at 25 (Figure 4). Then the inelastic yarn is moved to the left over gone needle, under oneneedle, so that the yarn is wrapped about the needle as shown at 21 (Figure 3) forming a reversing closed stitch shown at 29 (Figure 4). Thereafter, the inelastic. yarn is moved again to the right over so that the yarn is wrapped about the needle as shown at 3I (Figure 3) toform a non-reversing closed stitch as shown at-V 33 (Figure 4), and continues to move to the right over one needle, under one needle, so that the yarn is wrapped about the needle as shown at 35 (Figure .3) forming a reversing closed stitch as shown at 31 (Figure 4). Then the inelastic yarn is moved to the shown at 41 (Figure left over one needle, under one needle, so that the yarn is wrapped about the needle as shown at 39 (Figure 3) forming a reversing closed stitch as shown at 4Iv (Figure 4). Then the inelastic yarn is moved to the right over one needle, under one needle, so that the yarn is wrapped about the needle as shown at 43 (Figure 3) forming a reversing closed stitch as shown at 45 (Figure 4). Thereafter, the inelastic yarn is movedto the left over two needles, under one needle, so that the yarn is wrapped about the needle as 3) to form a non-reversing closed stitch as shown at 49 (Figure 4) and continues to vmove to the right over one needle, under one needle, so that the yarn is wrapped l about the needle as shown at 5I (Figure 3) .forming a reversing closed stitch as shown 'at 53 (Figure 4). This constitutes one repeat, which is duplicated throughout the length of the fabric.

The relative movements of the elastic. yarns IU and inelastic yarns I2 cause the interknitting of the inelastic yarns and the tying in of the l' staggered points, as indicated at Figure 4, such elastic yarns come out straight' fabric, as is diagrammatically elastic yarns in the manner more clearlyillustrated in Figure 4 of the drawing, from which Y it will be observed that theelastic yarns lie in 1 a plane between the chain loops and the floats,

connecting the chains. It will be further observed that the inelastic yarns pass back and forth between adjacent needles for several courses and then pass over to a third needle and that the number of courses betweenv consecutive bights of elastic yarn is equal to the number of chains or wales between such bights.

Attention is particularly called to that the Yelastic yarns the fact elastic yarns are laid in zig-zag directions as illustrated in Figures 1 and 2, and are hung at I9 and 2I in in the completed 5. Thus the elastic yarns,

a wrinkled effect in thefabric. Moreover, the straightening out of the elastic yarnsrelatively shifts and gathers in coursewise VVdirection the loops of Yinelastic yarns constituting the base fabric, with the result that a considerable increase in stretchability and snap is imparted to the fabric. Also, as a resultof the straighteningV of the elastic yarns and the shifting and gathering of the loopsof the inelastic yarns, there is produced on one 4face ofthe fabric a distinctive grogram-like surface appearance, AVas diagrammatically illustrated inFigure 5.1` y i I0 vare Vnecessarily laidlunder tension. Because of this, although the What I claim is:

1. A warp knit fabric consisting of two sets of Warp yarns, one set being knitted into loops constituting successive courses, the loops in certain of said courses at spaced intervals in the fabric being of the non-reversing closed type, the loops in the remaining courses in the fabric being of the reversing closed type, and the other set of yarns being laid into the fabric in zig-zag directions and hung unto said non-reversing closed loops.

2. A Warp knit fabric consisting of two sets `of warp yarns, one set consisting of inelastic yarns and the other set consisting of elastic yarns, the set of inelastic yarns being knitted into loops constituting successive courses, the loops in certain of said courses at spaced intervals in the fabric being of the non-reversing closed type, and the loops in the remaining courses in the fabric being of the reversing closed type, and the set of elastic yarns being laid into the fabric in zigzag directions and hung unto said non-reversing closed loops.

3. In a method of making warp fabric from two sets of yarns, the steps of: knitting one set of yarns into loops for the formation of spaced series of multiple courses and of a course intermediate each series by lapping said one set of yarns in reverse direction to form reversing closed loops throughout the courses of each spaced series, and lapping said one set of yarns in non-reverse direction to form. non-reverse closed loops throughout the courses intermediate each series; and laying in Without knitting into loops the other set of yarns by lapping said other set of yarns continuously in one direction in relation to one series of multiple courses of reversing closed loops, and continuously in the reverse direction in relation to the adjacent series of multiple courses of reversing closed loops, whereby to hang the yarns of said other set unto the non-reversing closed loops of the course intermediate said series.

4. In a method of making warp knit fabric from a set of inelastic yarns and a set of elastic yarns, the steps of: knitting the set of inelastic yarns into loops forthe formation of spaced series of multiple courses and of a course intermediate each series, by lapping said set of inelastic yarns in reverse direction to form reversing closed loops throughout the courses of each of said spaced series; and lapping said set of inelastic yarns in non-reverse direction to form non-reversing closed loops throughout the course intermediate each series; and laying in without knitting into loops the set of elastic yarns by looping said set of elastic yarns continuously in one direction in relation to one series of multiple courses of reversing closed loops and continuously in the reverse direction in relation to the adjacent series of multiple courses of reversing closed loops, whereby to hang the elastic yarns onto the non-reversing closed loops of the course intermediate said series.

5. A warp knit fabric comprising two sets of warp yarns, one of said sets forming Warpwise extending rows of loops arranged in courses, each of the yarns of said last named set forming alternately reversing and non-reversing loops in consecutive rows and successive courses, the loops of one row being connected with loops of another row by floats integral therewith, and the other of said sets forming zig-zag floats having relatively straight sections each extending across a plural-H ity of rows and a plurality of courses, said sections being connected by bights adjacent to nonreversing loops formed by said rst set, and the number of rows and courses traversed by the respective straight sections aforesaid being equal.

6. The method of knitting warp fabric from two sets of yarns, one of which is elastic and the other relatively inelastic, which comprises knitting from said inelastic yarns a plurality of warpwise extending rows of loops, each such yarn forming alternately reversing and non-reversrows and courses traversed by a straight section being equal.

CHAS. R. BURNS. 

